双煤层错距开采优选及对隔水关键层影响研究  

Optimal selection of staggered distance mining in double seams and its influence on water-resisting key strata

作　　者：孙学阳[1,2] 卢明皎 李成 苗霖田[3] SUN Xueyang;LU Mingjiao;LI Cheng;MIAO Lintian(School of Geology and Environment,Xi’an University of Science and Technology,Xi’an,Shaanxi 710054,China;Key Laboratory of Mine Geological Hazards Mechanism and Control,Xi’an,Shaanxi 710054,China;Key Laboratory of Coal Resources Exploration and Comprehensive Utilization,Xi’an,Shaanxi 710054,China)

机构地区：[1]西安科技大学地质与环境学院,陕西西安710054 [2]矿山地质灾害成灾机理与防控重点实验室,陕西西安710054 [3]煤炭资源勘查与综合利用重点实验室,陕西西安710054

出　　处：《采矿与安全工程学报》2021年第1期51-57,67,共8页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(41272388)。

摘　　要：为探索双煤层开采错距最优方案和对覆岩隔水关键层的影响,以榆神矿区某矿地质条件为背景,采用FLAC^(3D)数值模拟手段,从开采错距分别为0,20,40,60,80 m这5种模拟方案中比选出最优方案,并基于Mohr-Coulomb强度准则与数值模拟结果,结合相似材料模拟实验,讨论了不同开采错距对覆岩隔水关键层的影响。研究表明,双煤层错距开采,致使工作面覆岩拉应力呈现"W"形分布。以错距煤柱顶板为中心,左右两侧30m范围内最大主应力呈"几"字形分布,该范围下沉值呈现峰状分布。最优错距为40 m,最不利错距为0 m。当双煤层开采错距20,40,60 m时隔水关键层塑性和断裂变形区范围小于55%,尤其是错距是40 m时,隔水关键层最为完整。错距0,80 m时塑性和破坏区范围超过72%,隔水关键层较破碎,基本丧失隔水性。通过优化开采错距方案,可以有效减小隔水关键层塑性和断裂变形区范围,有利于保持隔水性能。In order to explore the optimal scheme of staggered distance mining in double seams and its influence on the water-resisting key strata,with the geological conditions of a mine in the Yushen mining area as background,the optimal schem was selected from five simulation schemes with staggered distance of 0,20,40,60,80 m by FLAC^(3D) numerical simulation method.Based on Mohr-Coulomb strength criterion and numerical simulation results,combined with similar material simulation experiments,the influence of different staggered distance mining on the water-resisting key strata of overlying strata was discussed.The results have shown that due to the staggered distance mining of double seams,the tensile stress of overlying strata on the working face shows a"W"distribution.With the staggered distance coal pillar roof as the center,the maximum principal stress in the range of 30 m on the left and right sides isΩ-shaped,and the subsidence value in this range presents a peak distribution.The optimal staggered distance is 40 m and the most unfavorable staggered distance is 0 m.When the staggered distance of double seams is 20,40,60 m,the range of plastic and fracture deformation zone of water-resisting key strata is less than 55%,especially when the staggered distance is 40 m,the water-resisting key strata is the most complete.When the staggered distance is 0 m and 80 m,the range of plasticity and failure zone is more than 72%,and the water-resisting key strata is broken,which basically loses water insulation.By optimizing the staggered distance mining schemes,the plasticity and fracture deformation zone of the water-resisting key strata can be effectively reduced,which is conducive to maintaining the water-resisting performance.

关 键 词：错距开采 数值模拟 最优错距 隔水关键层 应力集中 

分 类 号：TD323[矿业工程—矿井建设]